difference in tenses

The most common usage would be to describe something that happened in the past before another time in the past.
Nadal, who had booked his place in the finals, decided to go to Paris instead.

Got it. So Nadal booked his place before deciding to go to Paris. i
Is that correct, which basically as you said, an event that has happened before another event in the past?

Also, are the other two sentences that I wrote, the past and present perfect, correct?

AnonymousGot it. So Nadal booked his place before deciding to go to Paris. iIs that correct, which basically as you said, an event that has happened before another event in the past?

Yes.

AnonymousAlso, are the other two sentences that I wrote, the past and present perfect, correct?

They are basically correct, although they

Thank you. Just curious, would it be also possible/correct if I added 'has' in the sentence you provided:

Nadal, who had booked his place in the finals, 'has' decided to go to Paris instead.

It would create an odd mixture of tenses. I would use booked or has booked in the first sentence if I used has in the second.

Thanks. So the use of 'had' in these first sentence is not mandatory. The sentence can be written with 'has booked or booked'. So basically this sentence can be written in many ways, using the past perfect or present perfect or just the past. Am I correct?

It can be written in many ways, yes. However, decide is an unusual verb in that the present continuous, is deciding, actually means that the person has not decided, but is thinking about what decision to make. This means that we tend to view the present perfect, has decided, as being equivalent to holds the opinion that or is planning t

Thanks for your explanation. But, I assume that there are sentences in which the past perfect is mandatory, unlike this example where various tenses can be used and still the sentence would be correct. Is what I said correct?

So these are all possible ways to write the sentence in different tenses:
Nadal, who had booked his place in the finals, decided to go to Paris instead.
Nada

Nadal, who had booked his place in the finals, decided to go to Paris instead. (Good)
Nadal, who booked his place in the finals, has decided to go to Paris instead. (Good)
Nadal, who has booked his place in the finals, has decided to go to Paris instead. (Good)

Thank you that was very helpful.
So in your last example where another tense would not work, it would be wrong to say ......... as he was her faithful companion for many years. Right?

Also, I just saw a tutorial on saying saying that it is not possible to use a simple past instead of a past perfect when a specific time is not mentioned. I got this from the ineternent want would like